A characterization of strongly chordal graphs

AbstractIn this paper, we present a simple charactrization of strongly chordal graphs. A chordal graph is strongly chordal if and only if every cycle on six or more vertices has an induced triangle with exactly two edges of the triangle as the chords of the cycle

la enseñanza y aprendizaje del derecho humano al buen trato para la formación del pensamiento social, apoyados en la Webquest con estudiantes del grado 5° de la institución Jaime Salazar Robledo

La presente investigación se centra en una de las finalidades de la educación, donde pensar lo social implica, preguntarse por el proceso para interpretar una realidad que no está dada para explicarla, sino que se construye y genera otras realidades con espacio y tiempo a partir de una minuciosa y continua diferenciación de las habilidades de pensamiento social, hasta llegar a su profundización. Por lo tanto, se incluye la escuela, como una de las entidades encargadas de interpretar las habilidades de pensamiento social en una práctica de enseñanza y aprendizaje del derecho humano fundamental al buen trato, apoyado de la webquest con los estudiantes del grado 5º de la Institución Educativa Jaime Salazar Robledo. De esta manera, se plantea la pregunta de investigación que consiste en ¿Qué habilidades de pensamiento social se identifican en una unidad didáctica de enseñanza y aprendizaje del derecho humano fundamental al buen trato, apoyado en la Webquest con estudiantes del grado 5° de la Institución Educativa Jaime Salazar Robledo?. La metodología de investigación se basa en el enfoque interpretativo que pretende profundizar y comprender un fenómeno social, como es el derecho humano fundamental al buen trato y se centra en el método de estudio de casos para interpretar la vida real desde un solo contexto, por lo que no tiene pretensiones de generalización sino, que busca profundizar en el mismo (Yin, 2009) & (Stake, 2005). De acuerdo a los resultados, se realiza una práctica educativa donde el pensamiento se relaciona con habilidades sociales como: la descripción y la explicación, las cuales caracterizan las maneras de pensar de un estudiante y docentes frente al conocimiento de un saber especifico, que se enlaza con la realidad circundante. También, se utiliza la webquest como una estrategia que potencializa la adquisición de habilidades sociales como la descripción y explicación de forma significativa en la enseñanza y aprendizaje.The following investigation centers itself to educational purposses, think socially implies thinking the process to understand a reality that has not been given for explanation. But it builds itself alongwhith other realities in time and space form a detailed and continuos definition from the skills of social thinking. For that matter, the school is added as one of the entities in charge to interpret the skills of social thinking in the learning and teaching of the fundamental legal righ of good treatment, as supported by the webquest from the 5 th grade of the Jaime Salazar Robledo institution , fron this, we get the question. What skills of social thinking we can indentifity in a learning unit of teaching learning about the fundamental right of good treatment, as supported by the students of 5th grade from the educational institution Jaime Salazar Robledo? The methodology of investigation focuses on the interpretation to deeply understand the social phenomena that is the fundamental right at good treatment and centers itself in the study by cases to understand the real life from a context with no pretentions of generalizing, but to focus on itself (Yin, 2009) and (Stake, 2005). According to the result you perform on educational practice where the thought relates with the social skills as description and explanation, which distinguishes the ways of a teacher and student thoughts for on specific knowledge on his reality. Also uses the webquest as on strategy that potentially can acquire the social skills as the description and explanation in a great significant way of teaching and learning

Single-sided CZT strip detectors

We report progress in the study of thick CZT strip detectors for 3-D imaging and spectroscopy and discuss two approaches to device design. Unlike double-sided strip detectors, these devices feature both row and column contacts implemented on the anode surface. This electron-only approach circumvents problems associated with poor hole transport in CZT that normally limit the thickness and energy range of double-sided strip detectors. The work includes laboratory and simulation studies aimed at developing compact, efficient, detector modules for 0.05 to 1 MeV gamma radiation measurements while minimizing the number and complexity of the electronic readout channels. These devices can achieve similar performance to pixel detectors for both 3-D imaging and spectroscopy. The low channel count approach can significantly reduce the complexity and power requirements of the readout electronics. This is particularly important in applications requiring large area detector arrays. We show two single-sided strip detector concepts. One, previously reported, features rows established with collecting contacts and columns with noncollecting contacts. Another, introduced here, operates on a charge sharing principle and establishes both rows and columns with collecting contacts on the anode surface. In previous work using the earlier strip detector concept we reported simulations and measurements of energy and spatial resolution for prototype 5- and 10-mm-thick CZT detectors. We now present the results of detection efficiency and uniformity measurements conducted on 5-mm-thick detectors using a specific configuration of the front-end electronics and event trigger. We discuss the importance of the detector fabrication processes when implementing this approach

The geopolitics of presence and absence at the ruins of Fort Henry

In recent years, scholars have examined the non- or more-than-human world from a variety of unique positions. This article draws on contemporary archaeology and assemblage theories in geography to put forward an understanding of everyday geopolitics that includes the presence of objects in the formation of state subjectivity. Our approach, however, reveals not only this disciplining force of objects but also the ontological absences that are also at the heart of post-structuralist theories of subjectivity. As such, the formation of object-oriented geopolitical subjectivity is also always haunted by these other affective forces that are part of being in the world. These theoretical considerations are substantiated in our study of the material culture of a military outpost in the highlands of northern Chile where the objects left behind by soldiers offer insight into the complexities of state subjectification and state–society relations in border regions

Readout and performance of thick CZT strip detectors with orthogonal coplanar anodes

We report progress in the study of CZT strip detectors featuring orthogonal coplanar anode contacts. The work includes laboratory and simulation studies aimed at optimizing and developing compact, efficient, high performance detector modules for 0.05 to 1 MeV gamma radiation measurements. The novel coplanar anode strip configuration retains many of the performance advantages of pixel detectors yet requires far fewer electronic channels to perform both 3-d imaging and spectroscopy. We report on studies aimed at determining an optimum configuration of the analog signal processing electronics to employ with these detectors. We report measurements of energy and spatial resolution in three dimensions for prototype 5 and 10 mm thick CZT detectors using a set of shaping and summing amplifiers

Dual encoding of muscle tension and eye position by abducens motoneurons

Extraocular muscle tension associated with spontaneous eye movements has a pulse-slide-step profile similar to that of motoneuron firing rate. Existing models only relate motoneuron firing to eye position, velocity and acceleration. We measured and quantitatively compared lateral rectus muscle force and eye position with the firing of abducens motoneurons in the cat to determine fundamental encoding correlations. During fixations (step), muscle force increased exponentially with eccentric eye position, consistent with a model of estimate ensemble motor innervation based on neuronal sensitivities and recruitment order. Moreover, firing rate in all motoneurons tested was better related to eye position than to muscle tension during fixations. In contrast, during the postsaccadic slide phase, the time constant of firing rate decay was closely related to that of muscle force decay, suggesting that all motoneurons encode muscle tension as well. Discharge characteristics of abducens motoneurons formed overlapping clusters of phasic and tonic motoneurons, thus, tonic units recruited earlier and had a larger slide signal. We conclude that the slide signal is a discharge characteristic of the motoneuron that controls muscle tension during the postsaccadic phase and that motoneurons are specialized for both tension and position-related properties. The organization of signal content in the pool of abducens motoneurons from the very phasic to the very tonic units is possibly a result of the differential trophic background received from distinct types of muscle fibers

Development of CZT strip detector modules for 0.05- to 1-MeV gamma-ray imaging and spectroscopy

We report progress in our study of cadmium zinc telluride (CZT) strip detectors featuring orthogonal coplanar anode contacts. We specifically report on the performance, characterization and stability of 5 and 10 mm thick prototype CZT detectors fabricated using material from several manufacturers. Our ongoing work includes laboratory and simulation studies aimed at optimizing and developing compact, efficient, high performance detector modules for 0.05 to 1 MeV gamma radiation measurements with space-based instrumentation. The coplanar anode strip configuration retains many of the performance advantages of pixel detectors yet requires far fewer electronic channels to perform both 3-d imaging and spectroscopy. Minimizing the channel count is important for large balloon or space instruments including coded aperture telescopes (such as MARGIE or EXIST) and Compton imaging telescopes (such as TIGRE or ACT). We also present plans for developing compact, space qualified imaging modules designed for integration into closely packed large area detector arrays. We discuss issues associated with detector module and array electronics design and development